Darlington Partners Capital Management filed an Amendment No. 1 to a Schedule 13G/A reporting no beneficial ownership of OneStream, Inc. The filing (CUSIP 68278B107) lists DPCM LP, Darlington Partner GP, LLC, Darlington Partners, L.P., Scott W. Clark and Ramsey B. Jishi as reporting persons and states 0 shares and 0% ownership for each. The cover shows address details and disclaims beneficial ownership under Rule 13d-3; signatures are dated 05/15/2026.
Positive
None.
Negative
None.
Insights
Amendment records zero holdings and disclaims group beneficial ownership.
The filing lists the reporting persons and related entities, providing identifying information and stating 0 shares / 0% for each. It reiterates the disclaimer under Rule 13d-3 and includes manager signatures dated 05/15/2026.
Impact is procedural: this document clarifies that these filers do not hold a reportable stake in OneStream. Future filings would be required if ownership changes.
Key Figures
Filing type:Amendment No. 1 to Schedule 13G/ACUSIP:68278B107Amount beneficially owned:0 shares+3 more
6 metrics
Filing typeAmendment No. 1 to Schedule 13G/Acover page
CUSIP68278B107Class A Common Stock
Amount beneficially owned0 sharesDPCM LP and each reporting person
Percent of class0%DPCM LP and each reporting person
Signature date05/15/2026signed by Scott W. Clark and Ramsey B. Jishi
Cover date referenced03/31/2026cover page entry
Key Terms
Schedule 13G/A, Beneficial ownership, Rule 13d-3
3 terms
Schedule 13G/Aregulatory
"Amendment No. 1 to a Schedule 13G/A"
A Schedule 13G/A is an amended public filing with the U.S. securities regulator that updates a previous Schedule 13G, disclosing when an individual or group holds a substantial (typically over 5%) stake in a company and is claiming a passive, non‑controlling intent. Investors monitor these updates because rising or falling holdings can signal changing confidence, potential future moves, or shifts in voting power — like watching a public ledger where large shareholders quietly adjust their positions.
Beneficial ownershipregulatory
"Amount beneficially owned: DPCM LP: 0"
Beneficial ownership means the person or entity that actually enjoys the benefits of owning shares or other assets — such as receiving dividends, voting rights, or price gains — even if the legal title is held in another name. For investors it matters because knowing who truly controls and profits from a company reveals who can influence decisions, exposes potential conflicts of interest or hidden concentration of power, and affects transparency and risk in the stock.
Rule 13d-3regulatory
"disclaims that it is, a beneficial owner, as defined in Rule 13d-3"
Rule 13d-3 defines who is treated as the beneficial owner of a company’s shares for U.S. securities disclosure rules — essentially anyone who has the power to vote or direct how shares are voted, or the power to buy or sell them, even if they don’t hold the certificates. For investors this matters because crossing certain ownership thresholds triggers public filing and disclosure obligations and signals potential control or influence, much like having the keys to a car implies you can drive it even if it’s registered to someone else.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
(Amendment No. 1)
OneStream, Inc.
(Name of Issuer)
Class A Common Stock
(Title of Class of Securities)
68278B107
(CUSIP Number)
03/31/2026
(Date of Event Which Requires Filing of this Statement)
Check the appropriate box to designate the rule pursuant to which this Schedule is filed:
Rule 13d-1(b)
Rule 13d-1(c)
Rule 13d-1(d)
schemaVersion:
SCHEDULE 13G
CUSIP Number(s):
68278B107
1
Names of Reporting Persons
Darlington Partners Capital Management, LP
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
0.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
0.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
0 %
12
Type of Reporting Person (See Instructions)
IA, PN
SCHEDULE 13G
CUSIP Number(s):
68278B107
1
Names of Reporting Persons
Darlington Partner GP, LLC
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
0.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
0.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
0 %
12
Type of Reporting Person (See Instructions)
HC, OO
SCHEDULE 13G
CUSIP Number(s):
68278B107
1
Names of Reporting Persons
Darlington Partners, L.P.
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
0.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
0.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
0 %
12
Type of Reporting Person (See Instructions)
PN
SCHEDULE 13G
CUSIP Number(s):
68278B107
1
Names of Reporting Persons
Scott W. Clark
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
UNITED STATES
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
0.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
0.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
0 %
12
Type of Reporting Person (See Instructions)
HC, IN
SCHEDULE 13G
CUSIP Number(s):
68278B107
1
Names of Reporting Persons
Ramsey B. Jishi
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
UNITED STATES
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
0.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
0.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
0 %
12
Type of Reporting Person (See Instructions)
HC, IN
SCHEDULE 13G
Item 1.
(a)
Name of issuer:
OneStream, Inc.
(b)
Address of issuer's principal executive offices:
191 N. Chester Street, Birmingham, MI 48009
Item 2.
(a)
Name of person filing:
Darlington Partners Capital Management, LP, a Delaware limited partnership ("DPCM LP")
Darlington Partner GP, LLC, a Delaware limited liability company ("DP GP")
Darlington Partners, L.P., a Delaware limited Darlington ("Darlington")
Scott W. Clark
Ramsey B. Jishi
DPCM LP is the investment adviser of private investment funds, including Darlington (together, the "Funds"). DP GP is the general partner of DPCM LP and the Funds. Mr. Clark and Mr. Jishi are the managers of DP GP. The Filers are filing this Schedule 13G jointly but not as members of a group, and each disclaims membership in a group. Each reporting person disclaims beneficial ownership of Common Stock except to the extent of that person's pecuniary interest therein. In addition, the filing of this Schedule 13G on behalf of Darlington should not be construed as an admission that it is, and it disclaims that it is, a beneficial owner, as defined in Rule 13d-3 under the Act, of any Common Stock covered by this Schedule 13G.
(b)
Address or principal business office or, if none, residence:
300 Drakes Landing Road, Suite 290, Greenbrae, CA 94904
(c)
Citizenship:
See Item 4 of the cover sheet for each reporting person.
(d)
Title of class of securities:
Class A Common Stock
(e)
CUSIP No.:
68278B107
Item 3.
If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)
Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)
Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)
Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)
Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)
An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)
An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)
A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)
A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)
A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)
A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J),
please specify the type of institution:
(k)
Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.
Ownership
(a)
Amount beneficially owned:
DPCM LP: 0
DP GP: 0
Darlington: 0
Scott W. Clark: 0
Ramsey B. Jishi: 0
(b)
Percent of class:
DPCM LP: 0%
DP GP: 0%
Darlington: 0%
Scott W. Clark: 0%
Ramsey B. Jishi: 0%
(c)
Number of shares as to which the person has:
(i) Sole power to vote or to direct the vote:
DPCM LP: 0
DP GP: 0
Darlington: 0
Scott W. Clark: 0
Ramsey B. Jishi: 0
(ii) Shared power to vote or to direct the vote:
DPCM LP: 0
DP GP: 0
Darlington: 0
Scott W. Clark: 0
Ramsey B. Jishi: 0
(iii) Sole power to dispose or to direct the disposition of:
DPCM LP: 0
DP GP: 0
Darlington: 0
Scott W. Clark: 0
Ramsey B. Jishi: 0
(iv) Shared power to dispose or to direct the disposition of:
DPCM LP: 0
DP GP: 0
Darlington: 0
Scott W. Clark: 0
Ramsey B. Jishi: 0
Item 5.
Ownership of 5 Percent or Less of a Class.
Ownership of 5 percent or less of a class
Item 6.
Ownership of more than 5 Percent on Behalf of Another Person.
If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required.
DPCM LP's clients, including Darlington, have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the Stock. No individual client's holdings of the Stock, other than those of Darlington, are more than five percent of the outstanding Stock.
Item 7.
Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
Not Applicable
Item 8.
Identification and Classification of Members of the Group.
Not Applicable
Item 9.
Notice of Dissolution of Group.
Not Applicable
Item 10.
Certifications:
By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.
By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.
SIGNATURE
After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.
Darlington Partners Capital Management, LP
Signature:
/s/ Scott W. Clark
Name/Title:
Manager
Date:
05/15/2026
Darlington Partner GP, LLC
Signature:
/s/ Scott W. Clark
Name/Title:
Manager
Date:
05/15/2026
Darlington Partners, L.P.
Signature:
/s/ Scott W. Clark
Name/Title:
Manager of Darlington Partners GP, LLC, general partner of Darlington Partners, L.P.
What does Darlington's 13G/A amendment say about OneStream (OS) ownership?
The amendment states that Darlington and related reporting persons hold 0 shares and 0% of Class A Common Stock. It includes entity names, addresses, and a disclaimer under Rule 13d-3 with signatures dated 05/15/2026.
Who are the reporting persons named in the Schedule 13G/A amendment?
Reporting persons are DPCM LP, Darlington Partner GP, LLC, Darlington Partners, L.P., and individuals Scott W. Clark and Ramsey B. Jishi. The filing provides their citizenship and principal office details.
Does the amendment indicate any control or voting power over OneStream shares?
No. The filing reports 0 sole and 0 shared voting and dispositive powers for each reporting person, indicating they do not claim control or voting authority over Class A Common Stock.
What dates are shown on the filing and signatures?
The cover references 03/31/2026 and the signatures by Scott W. Clark and Ramsey B. Jishi are dated 05/15/2026. The document is identified as Amendment No. 1 to the Schedule 13G/A.
